Used the AC Cobra on Monaco and the countach on Deep Forest Raceway, both fully tuned.
Two things that i found handy after crying my eyes out on that event:
1) Do not forget the aero parts on the countach, helps greatly with cornering and stability in DFR.
2) If you do not have any of the opponent car, I suggest you restart your race until there's no Chaparral 2J or Tooyta 7 in the first 6 positions.
3) Get someone behind you to massage you while applying point 2., repeat point 2. about one hundred times until you might have a chance to win.
4) Drive
5) Rage at what you get in return of winning the event.